Abstract: The importance of the seed bank in soil can be understood by discussion about the seeds'numberand dynamics from dispersal input to output through germination ,predation and death.The seedbank partly reflects the history of the communities and can play an important role in therestoration of degraded land.So,the composition and size structures of soil seed bank werediscussed in the paper,Meanwhile,the effects of many factors,which are successional series, masting,size and age of seed, physical environment,disturbance,buriedseed depth,togetherwith some biological factors, on dynamics of the seed bank.At last,more attentions were paid tothe relationships between animals(dispersal and predation)and seed bank due to their increasing importance.

Key words: climate change, Great Xing’an Mountains, fire danger, forest fire danger rating.